Method and Electronic Device for Performing Migration Operation for Distributed Unit Scaling

This application is a bypass continuation application of International Application No. PCT/KR2024/008643, filed on Jun. 21, 2024, which claims priority to Korean Patent Application No. 10-2023-0084484, filed on Jun. 29, 2023, and Korean Patent Application No. 10-2023-0114605, filed on Aug. 30, 2023, in the Korean Intellectual Property Office, the disclosures of which are incorporated by reference herein in their entireties.

The present disclosure relates to a method and electronic device for performing a migration operation for distributed unit (DU) scaling.

In communication industries, technologies for a virtualized radio access network (RAN), i.e., vRAN, are growing rapidly. The existing hardware-based RAN requires specific hardware to perform each function for communication, and mobile carriers have needed to build a RAN with hardware components from the same manufacturer because of issues such as hardware compatibility. On the other hand, vRAN is not hardware-based but software-based RAN, and functions for communication of vRAN may be performed with software components. In other words, vRAN has no need for specific hardware to perform functions for communication, and the software components of vRAN may be executed by a universal server device to perform functions for communication. Accordingly, mobile carriers do not depend on products from a single manufacturer but use products from various manufacturers to build vRAN.

The present disclosure may be implemented in various ways including a method, a system, a device or a computer program stored in a computer-readable storage medium.

According to an aspect of the disclosure, a method performed by an electronic device may be provided. The method may include migrating a cell context for a target cell, the cell context being included in at least one of a first radio link control (RLC) layer, a first medium access control (MAC) layer or a first physical (PHY) layer, to at least one of a second RLC layer, a second MAC layer or a second PHY layer, the first MAC layer, the first RLC layer, and the first PHY layer being in a first distributed unit (DU), and the second MAC layer, the second RLC layer, and the second PHY layer being in a second DU; configuring, for the target cell, a connection between the first RLC layer and the second MAC layer, and identifying whether the target cell is in a state of being available for communication; migrating, from the first RLC layer to the second RLC layer, user equipment (UE) contexts for one or more target UEs among UE contexts for a plurality of UEs associated with the target cell; and switching a F1-U interface for the one or more target UEs from the first DU to the second DU, and configuring a connection between the second RLC layer and the second MAC layer for the one or more target UEs.

The method may further include, based on the migrating of the cell context for the target cell, switching a fronthaul interface for the target cell from the first DU to the second DU.

The method may further include, based on the migrating of the cell context for the target cell, migrating the UE contexts for the plurality of UEs included in at least one of the first MAC layer or the first PHY layer to at least one of the second MAC layer or the second PHY layer.

The method may further include, based on identifying that the target cell is in the state of being available for communication, removing the cell context for the target cell and the UE contexts for the plurality of UEs from at least one of the first MAC layer or the first PHY layer.

The migrating, from the first RLC layer to the second RLC layer, the UE contexts for the one or more target UEs comprises selecting the one or more target UEs from among the plurality of UEs.

The method may further include, based on the migrating, from the first RLC layer to the second RLC layer, the UE contexts for the one or more target UEs, removing the UE contexts for the one or more target UEs from the first RLC layer.

The method may further include, based on the migrating, from the first RLC layer to the second RLC layer, the UE contexts for the one or more target UEs, removing the cell context for the target cell from the first RLC layer.

The method may further include, identifying a determination of a scaling-out for the first DU or a determination of a scaling-in for the first DU.

The method may further include, based on the identifying of the determination of the scaling-out for the first DU, generating the second DU and configuring a midhaul interface between the second DU and a centralized unit (CU).

The method may further include, based on the identifying the determination of the scaling-in for the first DU, configuring a midhaul interface between the second DU and a CU.

The method further includes, based on identifying that the target cell is not in the state of being available for communication, re-performing migration of the cell context for the target cell from at least one of the first RLC layer, the first MAC layer or the first PHY layer to at least one of the second RLC layer, the second MAC layer or the second PHY layer.

According to an aspect of the disclosure, a non-transitory computer-readable recording medium having recorded thereon a program that is executed by at least one processor of an electronic device to perform the above-method may be provided.

According to an aspect of the disclosure, an electronic device may be provided. The electronic device may include: memory storing one or more instructions; and at least one processor configured to execute the one or more instructions stored in the memory. The one or more instructions, when executed by the at least one processor individually or collectively, cause the electronic device to: migrate a cell context for a target cell, the cell context being included in at least one of a first radio link control (RLC) layer, a first medium access control (MAC) layer or a first physical (PHY) layer, to at least one of a second RLC layer, a second MAC layer or a second PHY layer, the first RLC layer, the first MAC layer, and the first PHY layer being in a first distributed unit (DU), and the second RLC layer, the second MAC layer, and the second PHY layer being in a second DU, configure, for the target cell, a connection between the first RLC layer and the second MAC layer, and identify whether the target cell is in a state of being available for communication, migrate, from the first RLC layer to the second RLC layer, user equipment (UE) contexts for one or more target UEs among UE contexts for a plurality of UEs associated with the target cell, and switch an F1-U interface for the one or more target UEs from the first DU to the second DU, and configure a connection between the second RLC layer and the second MAC layer for the one or more target UEs.

The one or more instructions, when executed by the at least one processor individually or collectively, cause the electronic device to, based on the cell context for the target cell being migrated, switch a fronthaul interface for the target cell from the first DU to the second DU.

The one or more instructions, when executed by the at least one processor individually or collectively, cause the electronic device to, based on the cell context for the target cell being migrated, migrate the UE contexts for the plurality of UEs included in at least one of the first MAC layer or the first PHY layer to at least one of the second MAC layer or the second PHY layer.

The one or more instructions, when executed by the at least one processor individually or collectively, cause the electronic device to, based on the target cell being identified as in the state of being available for communication, remove the cell context for the target cell and the UE contexts for the plurality of UEs from at least one of the first MAC layer or the first PHY layer.

The one or more instructions, when executed by the at least one processor individually or collectively, cause the electronic device to select the one or more target UEs from among the plurality of UEs.

The one or more instructions, when executed by the at least one processor individually or collectively, cause the electronic device to, based on the UE contexts for the one or more target UEs being migrated from the first RLC layer to the second RLC layer, remove the UE contexts for the one or more target UEs from the first RLC layer.

The one or more instructions, when executed by the at least one processor individually or collectively, cause the electronic device to, based on the UE contexts for the one or more target UEs being migrated from the first RLC layer to the second RLC layer, remove the cell context for the target cell from the first RLC layer.

The one or more instructions, when executed by the at least one processor individually or collectively, cause the electronic device to, identify a determination of a scaling-out for the first DU or a determination of a scaling-in for the first DU.

The one or more instructions, when executed by the at least one processor individually or collectively, cause the electronic device to, based on the target cell being identified as not in the state of being available for communication, re-perform migration of the cell context for the target cell from at least one of the first RLC layer, the first MAC layer or the first PHY layer to at least one of the second RLC layer, the second MAC layer or the second PHY layer.

Various modifications may be made to embodiments of the present disclosure, which will be described more fully hereinafter with reference to the accompanying drawings. The present disclosure should be understood as not limited to particular embodiments but including all the modifications, equivalents and replacements which belong to technical scope and ideas of the present disclosure.

A detailed description of a related well-known technology that is likely to unnecessarily obscure the gist will be omitted herein. Ordinal numbers (e.g., first, second, etc.) as herein used are to distinguish components from one another. Unless the context clearly indicates otherwise, the singular forms “a”, “an”, and “the” are to be understood to include plural objects.

It is to be understood that blocks of each flowchart and combinations of flowcharts may be performed by one or more computer programs including computer-executable instructions. The one or more computer programs may be stored all in a single memory or may be distributed in many different memories.

All functions or operations as described in the specification may be processed by a single processor or a combination of processors. The single processor or the combination of processors are circuitries for performing processing, which may include an application processor (AP), a communication processor (CP), a graphical processing unit (GPU), a neural processing unit (NPU), a microprocessor unit (MPU), a system on chip (SoC), an integrated chip (IC), etc.

An embodiment of the present disclosure will now be described in detail with reference to accompanying drawings so as to be readily practiced by those of ordinary skill in the art. However, the embodiments of the present disclosure may be implemented in many different forms, and not limited thereto as will be discussed herein. Prior to describing the disclosure in detail, the terms used in the specification may be defined or understood as follows.

When one component is “connected” or “coupled” to another component, the one component may be directly connected or coupled to the other component. However, unless otherwise defined, it is also understood that the one component may be indirectly connected or coupled to the other component via another new component. Furthermore, ‘connection’ may include wireless connection or connection by wire.

Throughout the specification, a component expressed with “˜unit”, “˜module”, or the like may be a combination of two or more components or may be divided by function into two or more. Each of the components may perform its major function and further perform part or all of a function served by another component. In this way, part of a major function served by each component may be dedicated and performed by another component.

Throughout the present disclosure, the expression “at least one of a, b or c” indicates only a, only b, only c, both a and b, both a and c, both b and c, all of a, b, and c, or variations thereof. In the present disclosure, the expression “a or b” may refer to “a”, “b”, “a and b” or variations thereof. Throughout the present disclosure, the expression “a (or b or c)” may indicate only a, only b, only c, both a and b, both a and c, both b and c, all of a, b, and c, or variations thereof.

In an embodiment of the present disclosure, the term “migrating” may include moving, duplicating, reproducing or synchronizing target information to be migrated included in an arbitrary space to another arbitrary space. In an embodiment of the present disclosure, the term “migrating” may include having the target information to be migrated (e.g., context information), which is included, stored or configured in space A (or device A or module A), included, stored or configured in space B (or device B or module B). In an embodiment of the present disclosure, the term “migrating” may include having the target information to be migrated (e.g., context information), which is included, stored or configured in space A (or device A or module A), included, stored or configured in space B (or device B or module B), and removing, deleting or releasing the target information to be migrated from space A (device A or module A).

In an embodiment of the present disclosure, “cell migration” may include migration of at least one of a context associated with a cell or an interface associated with the cell. For example, “cell migration” may include migration of a cell context. For example, “cell migration” may include migration of a cell context and a user equipment (UE) context for a UE associated with the cell. In an embodiment of the present disclosure, “UE migration” refers to migration on a UE basis, which may include migration of a UE context. In an embodiment of the present disclosure, “UE migration” may include migration of an interface for user data (e.g., F1-U interface).

In an embodiment of the present disclosure, “connection relationship” may include a meaning of “access relationship”, “inclusion relationship”, “attachment relationship” or “matching relationship”. For example, “connected” may include a meaning of “accessing”, “included in”, “attached” or “matched”. In an embodiment of the present disclosure, “connection” may include a meaning of availability of wired/wireless data communication. For example, “A and B being connected” may include a meaning of availability of data communication between A and B, i.e., availability of data transmission/reception with each other.

In an embodiment of the present disclosure, “configuring” may include a meaning of “generating”, “activating”, “connecting”, “establishing”or “initiating”.

In an embodiment of the present disclosure, “releasing” may include a meaning of “removing”, “deactivating”, “interrupting/terminating”or “cutting off”.

In an embodiment of the present disclosure, “module A performing operation B” may include “module A directly performing operation B” or “module A controlling module C to perform operation B”.

In an embodiment of the present disclosure, “a UE associated with a cell” may include a UE connected to a cell, a UE communicating with an RU including a cell (i.e., transmitting/receiving data), a UE receiving a communication service through a cell, a UE transmitting/receiving data through a cell, a UE connecting to a core network through a cell, a UE included in a range of a cell, a UE requesting a radio resource of a cell, a UE allocated a radio resource of a cell, or the like.

In an embodiment of the present disclosure, “interface” may include a meaning of a module enabling data transmission/reception. In an embodiment of the present disclosure, “interface” may include a meaning of connection relationship. In an embodiment of the present disclosure, “interface” may include a meaning of a data transmit/receive path. In an embodiment of the present disclosure, “establishing an interface between A and B” may include configuring A and B to transmit or receive data to or from each other and to process the received data.

In an embodiment of the present disclosure, “scale-out for a DU” and “scaling-out for a DU” may include adding a new DU to a DU pool including DUs. In an embodiment of the present disclosure, “scale-out for a DU” and “scaling-out for a DU” may include migrating a cell included in a DU to another DU (e.g., the newly added DU).

In an embodiment of the disclosure, “scale-in for a DU” and “scaling-in for a DU” may include removing a DU from the DU pool. In an embodiment of the present disclosure, “scale-in for a DU” and “scaling-in for a DU” may include migrating a cell included in a DU to another DU (e.g., an existing DU).

1 FIG. is a diagram illustrating an example of a wireless communication system architecture, according to an embodiment of the present disclosure.

110 120 110 In an embodiment of the present disclosure, a wireless communication system may include a core networkand a radio access network (RAN). The core networkmay be a platform network including e.g., user authentication information for each mobile carrier and connected by wire through optical cables to servers and systems of various service companies.

120 128 1 128 2 128 3 128 4 128 5 128 6 124 1 124 2 124 3 124 4 122 120 120 In an embodiment of the present disclosure, the RANmay include at least one radio unit (RU)_,_,_,_,_, and_, at least one distributed unit (DU)_,_,_and_, and a centralized unit (CU). In an embodiment of the present disclosure, the RANmay include a virtualized radio access network (vRAN) system, without being limited thereto. For example, the RANmay include a 5G system (5GS), 4GS, or other wireless communication system, and may refer to a future-developed wireless communication system.

122 122 122 122 122 In an embodiment of the present disclosure, the CUmay be an entity that performs functions of some of protocol layers of a network. For example, the CUmay be an entity that performs network functions of a radio resource control (RRC) layer and a packet data convergence protocol (PDCP) layer, but the functions that may be processed by the CUare not limited to the functions of the aforementioned RRC layer and PDCP layer. For example, the CUmay perform functions of setting quality of service (QoS), reordering packets, security setting and processing, etc. For example, the CUmay refer to a virtualized CU (vCU) of the vRAN system, but is not limited thereto.

122 1 122 124 1 124 2 124 3 124 4 122 124 1 124 2 124 3 124 4 The single CUmay be connected to N DUs, where N may be an integer greater than. The CUand the DUs_,_,_and_may be connected by an interface. For example, the interface between the CUand the DUs_,_,_and_may be an F1 interface (or midhaul interface). For example, the F1 interface may include F1-C, an F1 interface of a control plane, and F1-U, an F1 interface of a user plane.

120 124 1 124 2 124 3 124 1 124 2 124 3 124 3 The RANmay include the DU_, the DU_and the DU_. The DUs-,_and_may perform the same function, so the DU_will now be focused as an example.

124 3 122 124 3 124 3 124 3 124 3 124 3 124 3 In an embodiment of the present disclosure, the DU_may be an entity that performs functions of some protocol layers of a network other than some other layers performed by the CU. For example, the DU_may be an entity that performs network functions (e.g., baseband functions) of a radio link control (RLC) layer, a medium access control (MAC) layer and a physical (PHY) layer, but functions that may be processed by the DU_are not limited to the functions of the RLC layer, MAC layer and PHY layer. For example, the DU_may perform a buffer function, a radio resource scheduling function, a data reprocessing function, etc. For example, the DU_may be a virtualized DU (vDU) of the vRAN system, but is not limited thereto. For example, the DU_may correspond to a component module, an arbitrary processing operation unit or arbitrary processing distribution unit, software, etc. For example, the DU_may correspond to a server.

1 124 1 128 1 128 2 124 2 128 3 128 4 124 3 128 5 128 6 124 3 128 5 128 6 124 3 128 5 128 6 1 FIG. A single DU may be connected to N RUs, where N may be an integer greater than. Referring to, the DU_may be connected to the RU_,. and the RU_, the DU_may be connected to the RU_,. and the RU_, and the DU_may be connected to the RU_,. and the RU_. In an embodiment of the present disclosure, the DU_and the RUs_and_may be connected by an interface. For example, the interface between the DU_and the RUs_and_may be a fronthaul interface.

128 1 128 2 128 3 128 4 128 5 128 6 128 6 The RUs_,_,_,_,_and_may perform the same function, so the RU_will now be focused as an example.

128 6 124 3 124 3 128 6 128 6 In an embodiment of the present disclosure, the RU_may be an entity that performs some of the functions of the PHY layer other than functions processed by the DU_. For example, the DU_may perform a function of a high-PHY layer, and the RU_may perform a function of a low-PHY layer. For example, the RU_may perform a function of data transmission/reception through an RF antenna.

In the existing RAN system, the DU may be connected one by one to a cell site including one or more RUs, and the throughput of a DU may be determined based on maximum traffic that may flow into the cell site. According to changes in traffic over time, the time at which the maximum traffic occurs is limited (e.g., 17:00 to 21:00), and there may be unused DU resources, i.e., available remaining resources at other times.

A virtualized DU (vDU) pooling technology to cut the one-by-one connection between the existing DU and the cell site (a set of RUs) and pool and virtualize DUs may be applied to a vRAN system according to an embodiment of the present disclosure. In this case, the number of servers required for building the RAN system may be reduced and capital expenditures (CAPEX) may be saved. Furthermore, power consumption may be reduced as compared to the existing RAN system, and the operating expenditure (OPEX) may be saved.

A vCU pooling technology to pool and virtualize CUs may be applied to the vRAN system according to an embodiment of the present disclosure. In this case, the number of servers required for building the RAN system may be reduced and capital expenditures (CAPEX) may be saved. Furthermore, power consumption may be reduced as compared to the existing RAN system, and the operating expenditure (OPEX) may be saved.

120 124 4 120 124 4 120 124 4 120 In an embodiment of the present disclosure, the RANmay use a vDU scaling method that uses server resources efficiently by dynamically scaling out or scaling in a DU depending on a current traffic condition. In the case of scaling-out, the DU_may be newly generated in the RAN, but is not limited thereto. For example, the DU_may have existed in the RAN. In the case of scaling-in, the DU_may have existed in the RAN.

124 3 124 3 124 4 124 4 124 3 124 4 124 3 124 4 124 3 124 4 126 1 FIG. 1 FIG. Hereinafter, the DU_may be denoted as the first DU_and the DU_may be denoted as the second DU_. In, in a case of scale-out, the first DU_may correspond to a source DU and the second DU_may correspond to a target DU. In, in a case of scale-in, the first DU_may correspond to a target DU and the second DU_may correspond to a source DU. The first DU_and the second DU_may be connected by an inter DU interface (Xd interface).

124 4 122 124 3 124 4 124 4 124 4 124 4 124 3 124 4 124 3 124 3 124 4 124 4 In an embodiment of the present disclosure, the scaling-out may include adding a new DU (e.g., the second DU_) into a DU pool for the CU. For example, when an amount of traffic to be processed by the first DU_included in the DU pool increases, the second DU_may be added to the DU pool. For example, the adding of the second DU_to the DU pool may include adding a module corresponding to the second DU_into the DU pool. For example, the adding of the second DU_to the DU pool may include initiating an operation of an additional server capable of processing data. When the capacity or capability for processing data of the first DU_(e.g., the existing server) reaches a limit, the scaling-out may be used to add the second DU_(a server with similar specifications as a non-limiting example) to the communication system. In this case, a cell whose data is to be processed by the first DU_may be migrated from the first DU_to the second DU_, allowing the data of the cell to be processed by the second DU_.

124 4 124 4 124 4 124 4 124 4 124 4 124 4 124 3 124 3 In an embodiment of the present disclosure, scaling-in may include removing the second DU_included in the DU pool. For example, when the amount of traffic to be processed by DUs included in the DU pool decreases, the second DU_may be removed from the DU pool. For example, the removing of the second DU_from the DU pool may include removing a module corresponding to the second DU_. For example, the removing of the second DU_from the DU pool may include interrupting the operation of a server that is processing the data. Using the scaling-in may reduce the number of servers whose operation is not required, and may save resources. For the scaling-in, a cell whose data is to be processed by the second DU_may be migrated from the second DU_to the first DU_, allowing the data of the cell to be processed by the first DU_.

124 4 124 4 124 4 124 3 124 3 124 3 124 3 124 4 124 4 124 3 124 4 124 4 In an embodiment of the present disclosure, apart from the scaling to add or remove the second DU_to or from the DU pool, the cell whose data is to be processed by the second DU_may be migrated from the second DU_to the first DU_to allow the data of the cell to be processed by the first DU_or the cell whose data is to be processed by the first DU_may be migrated from the first DU_to the second DU_to allow the data of the cell to be processed by the second DU_. For example, the cell may be migrated from the first DU_having a large amount of traffic to the second DU_having a relatively small amount of traffic to allow the data of the cell to be processed by the second DU_.

2 FIG. is a diagram illustrating an example of performing DU scaling in a radio access network (RAN), according to an embodiment of the present disclosure.

210 240 210 240 210 240 240 An Operations, Administration, and Maintenance (OAM) modulemay determine scaling-out or scaling-in for a first DU. In an embodiment of the present disclosure, the OAM modulemay determine scaling-out to add a new DU to a DU pool that includes the first DU. In an embodiment of the present disclosure, the OAM modulemay determine scaling-in to remove the first DUfrom the DU pool that includes the first DU.

210 250 212 240 210 250 240 210 250 210 250 210 250 The OAM modulemay generate a second DUinby determining scaling-out for the first DU. In an embodiment of the present disclosure, the OAM modulemay configure the second DU, which is a new DU to the DU pool that includes the first DU. In an embodiment of the present disclosure, the OAM modulemay activate the inactive second DU. In an embodiment of the present disclosure, the OAM modulemay configure the second DUfor an existing server device in operation. In an embodiment of the present disclosure, the OAM modulemay initiate operation of an additional server device and configure the second DUfor the additional server device.

210 240 250 210 250 220 210 250 230 220 214 210 250 220 230 220 230 220 2 FIG. The OAM modulemay migrate a target cell associated with the first DUto the second DU. The OAM modulemay configure a connection between the second DUand a CU. In an embodiment of the present disclosure, the OAM modulemay register the second DUin a midhaul splitter modulefor the CU, in. For example, the OAM modulemay configure (or generate) a midhaul interface for connecting the second DUto the CU. Although the midhaul splitter moduleis shown inas a separate module from the CU, it is not limited thereto. For example, the midhaul splitter modulemay be included in the CU.

210 250 270 210 250 260 270 216 210 250 270 260 270 260 270 2 FIG. The OAM modulemay configure a connection between the second DUand a RU. In an embodiment of the present disclosure, the OAM modulemay register the second DUin a fronthaul splitter modulefor an RU, in. For example, the OAM modulemay configure (or generate) a fronthaul interface for connecting the second DUto the RU. Although the fronthaul splitter moduleis shown inas a separate module from the RU, it is not limited thereto. For example, the fronthaul splitter modulemay be included in the RU.

210 240 250 218 210 250 210 240 250 The OAM modulemay migrate contexts included in the first DUto the second DU, in. Contexts included in a DU may include system information, a scheduling context, control information, frequency resource information, spatial resource information, a UE context, or an RU context. In an embodiment of the present disclosure, the OAM modulemay migrate a cell context for the target cell and a UE context to the second DU. For example, the OAM modulemay synchronize the cell context and UE context of the first DUwith the second DU.

240 250 While the target cell is being migrated from the first DUto the second DU, UEs associated with the target cell may be cut off from the wireless communication system. For example, while the fronthaul interface is being migrated, the UEs associated with the cell may not receive communication services through the target cell. When the migrating of the fronthaul interface requires longer time, i.e., time taken for the UEs associated with the target cell to be cut off from the wireless communication system exceeds a reference time, the UEs associated with the target cell may find another cell to perform a connecting operation thereto, and a lot of computing resources may be used in the procedure for the UE to find and connect to the other cell. Hence, a cell migration method that prevents the time taken for the UEs associated with the target cell to be cut off from the wireless communication system from exceeding the reference time may be required. The reference time may be so short that the user of the UE is unable to recognize the cut-off from the communication system. The reference time may be determined by a mobile carrier.

210 240 250 210 240 240 250 210 214 216 218 In an embodiment of the present disclosure, the OAM modulemay quickly switch over the target cell from the first DUto the second DUwithin a preset time (e.g., the reference time). For example, the OAM modulemay migrate all the midhaul interface, the fronthaul interface, a UE context and a cell context included in each layer of the first DUat the same time from the first DUto the second DUwithin the preset time. In other words, the OAM modulemay simultaneously perform the aforementioned operations,andfor cell migration in a set time. In this case, migration operation timing of all the modules associated with the migration operation needs to be synchronized, and when the synchronization of the operation timing is not guaranteed, it may cause overall system instability. Furthermore, migrating plenty of data at a time within a set time may be hardly implemented on an actual system.

210 240 250 210 240 250 240 240 250 250 270 240 250 260 2 FIG. In an embodiment of the present disclosure, the OAM modulemay migrate the target cell from the first DUto the second DUon a UE basis. For example, the OAM modulemay migrate a plurality of UEs included in the target cell from the first DUto the second DUon a UE basis. In this case, while the target cell is being migrated, a first UE of the target cell is connected to the first DUso that data of the first UE may be processed by the first DU, and a second UE of the target cell is connected to the second DUso that data of the second UE may be processed by the second DU. Accordingly, referring to, the RUmay be connected to both the first DUand the second DUthrough the fronthaul splitter moduleto transmit and receive data.

260 240 250 260 240 270 240 240 270 250 270 250 250 270 260 260 In the case of migrating the target cell on a UE basis, the fronthaul splitter modulemay transmit data from the first UE to the first DUand transmit data from the second UE to the second DU. For example, the fronthaul splitter modulemay activate a fronthaul interface between the first DUand the RUto transmit data of the first UE to the first DUor transmit data from the first DUto the RU, and activate a fronthaul interface between the second DUand the RUto transmit data of the second UE to the second DUor transmit data from the second DUto the RU. Hence, to process data of a plurality of UEs associated with the target cell, the fronthaul splitter moduleneeds to quickly switch paths (or activate an interface) between DU and RU, and for high-speed switching, the fronthaul splitter modulemay need a lot of computing resources. The high-speed switching may also deteriorate system stability and cause operation instability.

240 250 270 240 250 Furthermore, in the case of migrating the target cell on a UE basis, the first DUand the second DUmay be connected for the single RUuntil the migrating of the target cell is completed, and an MAC layer of the first DUand an MAC layer of the second DUmay simultaneously schedule radio resources of the target cell. Hence, complexity of implementation on the system may increase and system stability may be lowered.

2 FIG. One or more operations described inas being performed by a module or unit may be performed by an electronic device (or at least one processor of the electronic device) that includes the module or unit.

3 FIG. is a diagram illustrating an example of performing DU scaling-out in a RAN, according to an embodiment of the present disclosure.

310 350 310 350 310 350 350 310 350 350 350 350 An OAM modulemay determine scaling-out for a first DU. For example, the OAM modulemay determine scaling-out to add a new DU to a DU pool to which the first DUbelongs. In an embodiment of the present disclosure, the OAM modulemay identify that scaling-out for the first DUis required, based on information about the first DU. For example, the OAM modulemay determine scaling-out for the first DUbased on traffic of the first DU, throughput (e.g., a maximum amount of available resources) of the first DU, currently available resource (e.g., an amount of remaining resources) of the first DU, etc.

310 360 312 310 360 360 310 360 310 360 360 310 360 310 360 The OAM modulemay initiate a second DU, in. In an embodiment of the present disclosure, the OAM modulemay initiate the second DUby generating the second DU. In an embodiment of the present disclosure, the OAM modulemay configure a new DU, which is the second DU. In an embodiment of the present disclosure, the OAM modulemay activate the inactive second DUto initiate the second DU. In an embodiment of the present disclosure, the OAM modulemay configure the second DUfor an existing server device in operation. In an embodiment of the present disclosure, the OAM modulemay initiate operation of an additional server device and configure the second DUfor the additional server device.

310 360 330 310 360 330 310 360 330 330 350 360 340 3 FIG. The OAM modulemay configure a connection between the second DUand a CU. For example, the OAM modulemay configure a midhaul interface for connecting the second DUto the CU. For example, the OAM modulemay generate a midhaul interface for connecting the generated second DUto the CU. As shown in, a CUmay be connected to a plurality of DUs, i.e., the first DUand a second DUby a plurality of midhaul interfaces through the midhaul splitter module.

310 350 320 310 320 350 360 310 320 The OAM modulemay transmit information about the determining of the scaling-out for the first DUto a scaling agent modulethat manages/handles DU scaling or cell migration. In an embodiment of the present disclosure, the OAM modulemay instruct the scaling agent moduleto perform a migration operation from the first DUto the second DUfor scaling-out. For example, the OAM modulemay provide information required for the scaling agent moduleto perform the migration operation.

320 350 350 360 320 350 360 370 320 350 360 370 320 352 354 356 350 362 364 366 360 The scaling agent modulemay identify the determining of scaling-out for the first DU, and perform a cell migration operation from the first DUto the second DU. In an embodiment of the present disclosure, for the cell migration operation, the scaling agent modulemay control at least one of the first DU, the second DU, an RUor an inter-unit interface. For example, the scaling agent modulemay transmit an instruction to at least one of the first DU, the second DUor the RU. For example, the scaling agent modulemay control at least some of an RLC layer, i.e., first RLC layer, an MAC layer, i.e., a first MAC layer, or a PHY layer, i.e., a first PHY layer, of the first DU, or an RLC layer, i.e., a second RLC layer, an MAC layer, i.e., a second MAC layer, or a PHY layer, i.e., a second PHY layer, of the second DU.

320 350 360 320 310 350 350 360 350 350 The scaling agent modulemay identify a target cell to be migrated from the first DUto the second DU. In an embodiment of the present disclosure, the target cell may be selected by the scaling agent moduleor the OAM modulefrom among one or more cells associated with the first DU, but is not limited thereto. For example, the target cell may be selected based on information (e.g., throughput, remaining resources, traffic, etc.) regarding the first DU, information regarding the second DU, information (e.g., traffic) regarding each cell associated with the first DU, etc. For example, the target cell may be randomly selected from among one or more cells associated with the first DU.

320 350 360 322 320 350 360 350 360 320 352 354 356 350 362 364 366 360 The scaling agent modulemay migrate, for scaling-out, a context associated with the target cell from the first DUto the second DUin. For example, the scaling agent modulemay control at least one of the first DUor the second DUto migrate the context associated with the target cell from the first DUto the second DU. The context associated with the target cell may include a cell context for the target cell itself, or a UE context for a UE associated with the target cell. In an embodiment of the present disclosure, the scaling agent modulemay migrate the context associated with the target cell included in at least one of the RLC layer, the MAC layeror the PHY layerof the first DUto at least one of the RLC layer, the MAC layeror the PHY layerof the second DU.

320 370 350 360 324 320 350 360 370 350 360 320 350 370 360 370 370 370 3 FIG. The scaling agent modulemay switch a fronthaul interface between the RUand the DU from the first DUto the second DUfor the target cell, in. For example, the scaling agent modulemay control at least one of the first DU, the second DUor the RUto switch the fronthaul interface from the first DUto the second DUfor the target cell. In an embodiment of the present disclosure, for the target cell, the scaling agent modulemay release the fronthaul interface between the first DUand the RU, and configure a fronthaul interface between the second DUand the RU. In other words, for the target cell, the RUmay be connected to one DU through the fronthaul interface. Hence, the RAN ofmay not include a fronthaul splitter module for providing a plurality of fronthaul interfaces between the RUand the plurality of DUs for the target cell.

370 In the meantime, in an embodiment of the present disclosure, the RUmay be connected to a single DU for the target cell, but an RU associated with a plurality of cells may be connected to a first DU for a first cell and to a second DU for a second cell. In other words, the RU may be connected to a plurality of DUs through a plurality of fronthaul interfaces on a cell basis. Furthermore, in an embodiment of the present disclosure, a single DU may be connected to a plurality of RUs through a plurality of fronthaul interfaces.

320 322 324 350 360 5 7 FIGS.to Detailed operations of the scaling agent modulemigrating a context associated with the target cell inand switching between fronthaul interfaces into migrate the target cell from the first DUto the second DUwill be described later with reference to.

320 310 320 310 320 310 3 FIG. The scaling agent moduleand the OAM moduleare separately shown in, but the disclosure is not limited thereto. For example, the scaling agent moduleand the OAM moduleare integrated in a single module, which may perform the functions and operations of the scaling agent moduleand the OAM module.

3 FIG. 350 360 350 360 The respective modules and units ofmay be software modules, hardware modules and/or a combination thereof. For example, the first DUand the second DUare software modules, which may be included/stored and executed in one hardware. For example, the first DUand the second DUmay be included/stored and executed in different hardware.

3 FIG. One or more operations described inas being performed by a module or unit may be performed by an electronic device (or at least one processor of the electronic device) that includes the module or unit.

4 FIG. is a diagram illustrating an example in which an electronic device determines scaling-out for a first DU, according to an embodiment of the present disclosure.

4 FIG. 4 FIG. 450 380 450 380 450 380 450 380 380 350 330 In, an example of a RAN before migration of a target cell may be illustrated. Referring to, one or more UEsmay be connected (or coupled, included or attached) to an RU. For example, the one or more UEsmay be connected (or coupled, included or attached) to a target cell of the RUto perform data communication through the target cell. For example, the one or more UEsmay be wirelessly connected to the RUto exchange information, data, packets, signals, etc., with the RAN. For example, the one or more UEsmay be connected (or coupled, included or attached) to the target cell of the RUand thus, connected (or coupled, included or attached) to a core network through the RU, the first DUand the CU.

330 410 410 412 1 412 2 412 3 450 410 412 1 412 2 412 3 450 412 1 412 2 412 3 450 412 1 4 FIG. In an embodiment of the present disclosure, the CUmay include a PDCP layer, and the PDCP layermay include UE contexts_,_and_for the one or more UEs. For example, the PDCP layermay be configured with the UE contexts_,_and_for the one or more UEs. The UE contexts_,_and_for the one or more UEsmay include one or more radio bearers (RBs). As shown in, the UE context_for the first UE may include a plurality of RBs. The number of RBs may correspond to the number of applications or services being performed by the UE.

350 352 354 356 352 440 1 440 2 440 3 450 352 440 1 440 2 440 3 450 440 1 440 2 440 3 450 440 1 4 FIG. In an embodiment of the present disclosure, the first DUmay include the RLC layer, the MAC layerand the high-physical (H-PHY) layer. The RLC layermay include UE contexts_,_and_for the one or more UEs. For example, the RLC layermay be configured with the UE contexts_,_and_for the one or more UEs. The UE contexts_,_and_for the one or more UEsmay include one or more radio bearers (RBs). The one or more RBs may include buffers. As shown in, the UE context_for the first UE may include a plurality of RBs.

330 350 330 420 350 430 330 350 420 430 340 330 350 420 430 340 The CUmay be connected to the first DUthrough a midhaul interface (i.e., F1 interface). In an embodiment of the present disclosure, the CUmay include an F1 message handler module, the first DUmay include an F1 message handler module, and the CUand the first DUmay be connected through the F1 massage handler modulesandand the midhaul splitter module. For example, an F1-C interface between the CUand the first DUmay be formed to go through the F1 message handler modulesandand the midhaul splitter module.

340 330 330 420 430 340 330 The midhaul splitter modulemay transmit F1 messages received from a plurality of DUs to the CU, and distribute F1 messages received from the CUto the plurality of DUs. The F1 message handler modulesandmay process the F1 messages input through the midhaul splitter module. The F1 messages may include information, data, signals, packets, etc., exchanged between the DU and the CU. For example, the F1 message may include control information.

330 350 340 410 330 352 350 340 410 330 352 350 340 4 FIG. In an embodiment of the present disclosure, the CUand the first DUmay exchange user data directly with each other without going through the midhaul splitter module. For example, the PDCP layerof the CUand the RLC layerof the first DUmay directly communicate the user data through the F1-U interface. This may prevent inefficient use of network resources by the midhaul splitter module. As shown in, the F1-U interface (or F1-U path) may provide user data communication between the PDCP layerof the CUand the RLC layerof the first DUwithout going through the midhaul splitter module.

330 410 350 352 In an embodiment of the present disclosure, a plurality of F1-U interfaces may be configured (or established or generated) for a single UE. For example, as many F1-U interfaces for one UE as the number of RBs configured for the UE may be configured. For example, an F1-U interface may be configured between the CU(e.g., PDCP layer) and the first DU(e.g., RLC layer) for each RB.

4 FIG. 350 360 380 350 380 350 380 350 356 380 350 356 Referring to, as it is before the cell is migrated from the first DUto the second DU, the fronthaul interface may be configured (or established or generated) between the RUand the first DUto handle communication between the RUand the first DU. In other words, the RUmay be connected to the first DU(e.g., the H-PHY layer) through the fronthaul interface. In an embodiment of the present disclosure, the RUand the first DU(e.g., the H-PHY layer) may exchange information, data, packets, signals, etc., with each other through the fronthaul interface.

350 350 360 360 360 362 364 366 350 360 4 FIG. In an embodiment of the present disclosure, an electronic device (e.g., a device for executing the OAM module) may determine scaling-out for the first DU. For example, the electronic device may determine scaling-out from the first DUto a new DU, the second DU, and generate (or form, initiate, or activate) the second DU. The second DUmay include the RLC layer, the MAC layerand the H-PHY layer. As shown in, the first DUand the second DUmay be connected through an inter-DU interface (e.g., Xd interface).

360 510 360 330 510 360 330 340 360 330 In an embodiment of the present disclosure, the electronic device may generate the second DU, and configure (or establish or generate) a midhaul interfacebetween the second DUand the CU. The midhaul interfacebetween the second DUand the CUmay be configured through the midhaul splitter moduleto handle communication between the second DUand the CU.

5 7 FIGS.to are diagrams illustrating examples in which an electronic device performs cell migration for DU scaling-out, according to an embodiment of the present disclosure.

5 7 FIGS.to 4 FIG. 5 6 FIGS.and The electronic device for performing the following operations inmay be different from or identical to the electronic device that performs the aforementioned operations of. In, an example in which an electronic device (e.g., a device for executing the scaling agent module) migrates a cell context for the target cell and a fronthaul interface according to an embodiment of the present disclosure may be illustrated.

350 350 360 350 360 350 350 380 350 The electronic device may identify a determination of scaling-out for the first DU. In an embodiment of the present disclosure, the electronic device may identify a determination of an OAM module of scaling-out from the first DUto the second DU. The electronic device may identify a target cell to be migrated from the first DUto the second DU. In an embodiment of the present disclosure, the electronic device may identify the target cell determined by the OAM module as a migration subject. In an embodiment of the present disclosure, the electronic device may determine a target cell among cells associated with (or included in or attached to) the first DU. The cells associated with the first DUmay include a cell of the RUconnected to the first DU.

5 FIG. 350 520 530 540 520 530 540 450 450 450 352 354 356 350 Referring to, the first DUmay include cell contexts,andfor the target cell. The cell contexts,andfor the target cell may include configuration information regarding a frequency band of the target cell, a radio resource scheduling method, a common signal to be transmitted to the one or more UEsassociated with the target cell, etc. Connection of the one or more UEsassociated with the target cell may be configured and managed based on the cell context for the target cell. The one or more UEsassociated with the target cell may include a UE included in an effective range of the target cell, a UE connected to the target cell, a UE attached to the target cell, a UE receiving a communication service through the target cell, a UE accessing a network through the target cell, etc. The cell contexts included in the respective RLC layer, MAC layerand H-PHY layerof the first DUmay be different from one another, different in part, or identical to each other.

350 360 520 530 540 350 360 520 530 540 352 354 356 350 362 364 366 360 520 352 350 362 360 530 354 350 364 360 540 356 350 366 360 5 FIG. The electronic device may migrate the target cell from the first DUto the second DU. Referring to, the electronic device may migrate the cell contexts,andfor the target cell included in the first DUto the second DU. In an embodiment of the present disclosure, the electronic device may migrate the cell contexts,andfor the target cell included in at least one of the RLC layer, the MAC layeror the H-PHY layerof the first DUto at least one of the RLC layer, the MAC layeror the H-PHY layerof the second DU. For example, the electronic device may migrate the cell contextincluded in the RLC layerof the first DUto the RLC layerof the second DU. For example, the electronic device may migrate the cell contextincluded in the MAC layerof the first DUto the MAC layerof the second DU. For example, the electronic device may migrate the cell contextincluded in the H-PHY layerof the first DUto the H-PHY layerof the second DU.

350 520 530 540 520 530 540 350 360 350 450 520 530 540 520 530 540 In an embodiment of the present disclosure, as the first DUincludes the cell context,orfor the target cell while the electronic device is migrating the cell context,orfor the target cell from the first DUto the second DU, the first DUmay process data for the target cell (e.g., data for communication of a UE associated with the target cell) and the communication of the one or more UEsassociated with the target cell may not be interrupted. In other words, even while the cell context,orfor the target cell is being migrated, the communication service through the target cell may be maintained without being interrupted. Accordingly, the migrating of the cell context,orfor the target cell may be performed without restriction of time.

360 350 520 530 540 360 520 530 540 350 520 362 360 520 352 350 530 364 360 530 354 350 540 366 360 540 356 350 In an embodiment of the present disclosure, the electronic device may migrate the target cell by configuring the target cell for the second DUbased on parameters that have been used to configure the target cell for the first DU. For example, the electronic device may generate (or configure) the cell context,orfor the target cell for the second DUby using a parameter that has been used to generate (or configure) the cell context,orfor the target cell for the first DU. For example, the electronic device may generate the cell contextfor the target cell for the RLC layerof the second DUby using a parameter that has been used to generate the cell contextfor the target cell of the RLC layerof the first DU. For example, the electronic device may generate the cell contextfor the target cell for the MAC layerof the second DUbased on a parameter that has been used to generate the cell contextfor the target cell of the MAC layerof the first DU. For example, the electronic device may generate the cell contextfor the target cell for the PHY layerof the second DUbased on a parameter that has been used to generate the cell contextfor the target cell of the PHY layerof the first DU.

520 530 540 350 360 350 520 530 540 360 520 530 540 350 360 In an embodiment of the present disclosure, the electronic device may duplicate (or reproduce) the cell contexts,andthemselves for the target cell included in the first DUto the second DU. For example, the electronic device may control the first DUto duplicate (or reproduce) the cell contexts,andfor the target cell to the second DU. For example, the cell contexts,andfor the target cell may be duplicated/reproduced from the first DUto the second DUthrough an inter-DU interface.

5 6 FIGS.and 550 450 354 364 360 550 450 364 360 550 450 354 350 550 450 354 364 360 350 550 450 354 364 360 550 450 350 360 Referring to, the electronic device may migrate UE contextsfor one or more UEsincluded in the MAC layerof the first DU to the MAC layerof the second DU. In an embodiment of the present disclosure, the electronic device may generate (or configure) the UE contextsfor the one or more UEsfor the MAC layerof the second DUbased on parameters that have been used to generate (or configure) the UE contextsfor the one or more UEsfor the MAC layerof the first DU. In an embodiment of the present disclosure, the electronic device may duplicate (or reproduce) the UE contextsthemselves for the one or more UEsincluded in the MAC layerof the first DU to the MAC layerof the second DU. For example, the electronic device may control the first DUto duplicate (or reproduce) and provide the UE contextsfor the one or more UEsincluded in the MAC layerto the MAC layerof the second DU. For example, the UE contextsfor the one or more UEsmay be duplicated/reproduced from the first DUto the second DUthrough the inter-DU interface.

6 FIG. 352 350 364 360 352 350 364 360 550 450 354 350 364 360 352 350 364 360 Referring to, the electronic device may configure (or establish, generate or activate) a connection between the RLC layerof the first DUand the MAC layerof the second DUfor DU scaling or migration of the target cell. In other words, the electronic device may configure (or activate) an interface for connection between the RLC layerof the first DUand the MAC layerof the second DU(e.g., the inter-DU interface). For example, the electronic device may migrate the UE contextsfor the one or more UEsincluded in the MAC layerof the first DUto the MAC layerof the second DU, and then configure a connection between the RLC layerof the first DUand the MAC layerof the second DU.

5 6 FIGS.and 380 350 360 520 530 540 350 360 380 350 380 360 520 530 540 350 360 380 350 380 360 550 450 364 360 380 350 360 550 450 364 360 380 350 360 Referring to, the electronic device may switch the fronthaul interface of the RUfor the target cell from the first DUto the second DU. For example, after migrating the cell contexts,andfor the target cell from the first DUto the second DU, the electronic device may release (or terminate, interrupt, or deactivate) the fronthaul interface between the RUand the first DUand establish (or initiate or activate) a fronthaul interface between the RUand the second DU. For example, as soon as the electronic device migrates the cell contexts,andfor the target cell from the first DUto the second DU, the electronic device may release the fronthaul interface between the RUand the first DUand establish a fronthaul interface between the RUand the second DU. For example, as soon as the electronic device migrates the UE contextsfor the one or more UEsto the MAC layerof the second DU, the electronic device may switch the fronthaul interface of the RUfor the target cell from the first DUto the second DU. For example, after migrating the UE contextsfor the one or more UEsto the MAC layerof the second DU, the electronic device may switch the fronthaul interface of the RUfor the target cell from the first DUto the second DU.

380 350 380 360 380 350 380 360 380 350 380 360 380 380 360 380 360 In an embodiment of the present disclosure, the releasing of the fronthaul interface between the RUand the first DUand the establishing of the fronthaul interface between the RUand the second DUmay be performed simultaneously. In an embodiment of the present disclosure, there may be a time difference between the releasing of the fronthaul interface between the RUand the first DUand the establishing of the fronthaul interface between the RUand the second DU. For example, the electronic device may release the fronthaul interface between the RUand the first DUand then establish a fronthaul interface between the RUand the second DU. In this case, there may be a time for which the RUis cut off from the RAN, the time being within a reference time, which may be so short that the user of the UE is unable to recognize the termination of the communication. For example, the electronic device may establish the fronthaul interface between the RUand the second DUand then release the fronthaul interface between the RUand the first DU.

6 FIG. 450 520 530 540 550 450 530 540 550 354 356 350 530 540 550 354 356 350 Referring to, when communication of the one or more UEsthrough the target cell is available after migration of the cell contexts,andfor the target cell, migration of the UE contextsfor the one or more UEsand switching of the fronthaul interface, the electronic device may remove (or delete) the migrated cell contextsandand UE contextsfrom the MAC layerand H-PHY layerof the first DU. In an embodiment of the present disclosure, the electronic device may identify that communication of the target cell is in an available state, and accordingly, remove (or delete) the cell contextsandand the UE contextsmigrated from the MAC layerand the H-PHY layerof the first DU. The communication available state may include a communication state that satisfies an arbitrary criterion such as a delay, a data processing rate, etc.

6 FIG. 450 380 366 364 360 352 350 330 450 380 366 364 360 352 350 330 450 366 364 360 352 350 Referring to, the one or more UEsincluded in the target cell may receive communication services through the RU, the H-PHY layerand MAC layerof the second DU, the RLC layerof the first DU, and the CU. In other words, the one or more UEsincluded in the target cell may connect to (or access) a core network through the RU, the H-PHY layerand MAC layerof the second DU, the RLC layerof the first DU, and the CU. That is, data for communication of the one or more UEsassociated with the target cell may be processed by the H-PHY layerand the MAC layerof the second DUand the RLC layerof the first DU.

7 FIG. is a diagram illustrating an example in which the electronic device migrates an F1-U interface and UE contexts for one or more UEs included in an RLC layer, according to an embodiment of the present disclosure.

440 1 440 2 440 3 450 352 350 362 360 440 1 440 2 440 3 352 350 440 1 440 2 440 3 352 360 440 1 440 2 440 3 352 350 362 360 350 440 1 440 2 440 3 352 362 360 440 1 440 2 440 3 350 360 The electronic device may migrate the UE contexts_,_and_for the one or more UEsincluded in the RLC layerof the first DUto the RLC layerof the second DUon a UE basis. In an embodiment of the present disclosure, the electronic device may use information (e.g., parameters or data) that has been used to generate (or configure) the UE contexts_,_and_for the RLC layerof the first DUto generate (or configure) the UE contexts_,_and_for the RLC layerof the second DU. In an embodiment of the present disclosure, the electronic device may duplicate (or reproduce) the UE contexts_,_and_themselves in the RLC layerof the first DUto the RLC layerof the second DU. For example, the electronic device may control the first DUto duplicate (or reproduce) the UE contexts_,_and_included in the RLC layerto the RLC layerof the second DUon a UE basis. For example, the UE contexts_,_and_may be duplicated/reproduced from the first DUto the second DUthrough an inter-DU interface on a UE basis.

450 352 350 362 360 450 352 350 362 360 450 In an embodiment of the present disclosure, the electronic device may migrate a plurality of UE groups including at least some of the one or more UEsassociated with the target cell in sequence from the RLC layerof the first DUto the RLC layerof the second DU. For example, the electronic device may sequentially migrate the plurality of UE groups in multiple rounds (or at multiple times). For example, the electronic device may migrate UE contexts for one or more first target UEs, which are at least some of the one or more UEsassociated with the target cell, and then migrate UE contexts for one or more second target UEs, which are at least some of UEs whose contexts have not been migrated. The electronic device may migrate the UE contexts from the RLC layerof the first DUto the RLC layerof the second DUon a UE basis until the one or more UEsassociated with the target cell are all migrated.

450 450 In an embodiment of the present disclosure, the electronic device may identify one or more target UEs to be migrated in the current round (or at a current time) among the one or more UEsassociated with the target cell. For example, the electronic device may select (or determine) one or more target UEs to be migrated in the current round (or at a current time) among the one or more UEsassociated with the target cell. For example, the electronic device may determine a migration sequence of UEs (or UE groups). For example, the electronic device may identify one or more target UEs determined by another electronic device.

350 360 362 360 352 350 360 350 330 350 330 360 330 360 330 360 330 360 330 360 450 330 350 In an embodiment of the present disclosure, the electronic device may switch the f1-U interface for the one or more target UEs from the first DUto the second DU. For example, after migrating the UE contexts for the one or more target UEs to the RLC layerof the second DUfrom the RLC layerof the first DU, the electronic device may switch the F1-U interface for the one or more target UEs to the second DUfrom the first DU. For example, the electronic device may release (or deactivate, cut off, interrupt, or remove) the F1-U interface between the CUand the first DUfor a UE whose UE context has been migrated, and configure (or activate, establish and generate) the F1-U interface between the CUand the second DU. For example, the configuring of the F1-U interface between the CUand the second DUand the releasing of the F1-U interface between the CUand the first DUmay be performed at the same time. For example, the configuring of the F1-U interface between the CUand the second DUmay be performed after the F1-U interface between the CUand the first DUmay be released. In the meantime, for a UE whose UE context has not been migrated among the one or more UEsfor the target cell, the F1-U interface between the CUand the first DUmay be maintained.

350 360 360 360 352 350 364 360 362 360 364 360 450 350 360 352 350 364 360 In an embodiment of the present disclosure, the electronic device may change (or switch) the RLC layer-to-MAC layer path for the one or more target UEs from the first DU-to-second DUpath to the second DU-to-second DUpath. For example, for the one or more target UEs, the electronic device may change (or switch) from the path from the RLC layerof the first DUto the MAC layerof the second DUto the path from the RLC layerof the second DUto the MAC layerof the second DU. The RLC layer-to-MAC layer path for a UE whose UE context has not been migrated among the one or more UEsfor the target cell may be maintained as the path from the first DUto the second DU(i.e., the path from the RLC layerof the first DUto the MAC layerof the second DU).

7 FIG. 440 1 380 366 364 360 352 350 330 440 3 380 366 364 362 360 330 352 350 362 360 As shown in, the first UE whose UE context_, F1-U interface and RLC-to-MAC path have not been migrated may access (or connect to) a core network through the RU, the H-PHY layerand the MAC layerof the second DU, the RLC layerof the first DUand the CUto receive communication services. On the other hand, the second UE whose UE context_, F1-U interface and RLC-to-MAC path have been migrated may access (or connect to) the core network through the RU, the H-PHY layer, MAC layerand RLC layerof the second DUand the CUto receive communication services. In other words, data about a UE that has not been migrated among data for the target cell may be processed by the RLC layerof the first DU, and data about a UE that has been migrated may be processed by the RLC layerof the second DU.

440 3 440 3 352 350 352 350 352 350 352 350 352 350 352 In an embodiment of the present disclosure, the electronic device may remove the UE context_for the UE whose UE context_, F1-U interface and RLC-to-MAC path have been migrated from the RLC layerof the first DU. For example, after migrating UE contexts for one or more target UEs, switching the F1-U interface and changing the RLC-to-MAC path, the electronic device may remove the UE contexts for the one or more target UEs from the RLC layerof the first DUregardless of migration of other UE contexts. For example, after migrating UE contexts for one or more target UEs, switching the F1-U interface and changing the RLC-to-MAC path, the electronic device may remove the UE contexts for the one or more target UEs from the RLC layerof the first DUbefore migrating UE contexts for other UEs to the RLC layerof the first DU. For example, the electronic device may remove UE contexts for a plurality of UEs associated with the target cell from the RLC layerof the first DUafter completing migration of the UE contexts for all the plurality of UEs associated with the target cell, switching of the F1-U interface and change of the RLC-to-MAC path. For example, the electronic device may periodically or aperiodically remove the UE contexts for the UEs whose migration has been completed from the RLC layerof the first DU.

352 350 362 360 352 362 350 520 352 440 1 440 2 440 3 352 The electronic device may migrate the UE contexts for all the UEs associated with the target cell from the RLC layerof the first DUto the RLC layerof the second DU. In an embodiment of the present disclosure, until the UE contexts for all the UEs associated with the target cell are migrated, it may select a target UE to be migrated, migrate a UE context for the selected target UE from the RLC layerto the RLC layer, switch the F1-U interface for the selected target UE, and change the RLC-to-MAC path. When there is no more UE to be migrated, i.e., when migration of the UE contexts for all the UEs associated with the target cell is completed, the electronic device may remove (or delete) information about the target cell from the first DU. For example, as the migrating of the target cell is completed, the electronic device may remove the cell contextfor the target cell from the RLC layer. For example, as the migrating of the target cell is completed, the electronic device may remove the UE contexts_,_and_from the RLC layer.

352 350 364 360 350 360 450 350 360 In an embodiment of the present disclosure, as the migrating of the target cell is completed, the electronic device may release (or interrupt, terminate or deactivate) the connection between the RLC layerof the first DUand the MAC layerof the second DU. In an embodiment of the present disclosure, as the migrating of the target cell is completed, the electronic device may release (or interrupt, terminate or deactivate) the interface between the first DUand the second DU. Along with the migration of the target cell, data for communication of the one or more UEsassociated with the target cell that has been processed by the first DUmay be processed by the second DU.

8 FIG. is a diagram illustrating an example of performing DU scaling-in in a RAN, according to an embodiment of the present disclosure.

810 850 810 850 850 810 850 810 850 850 An OAM modulemay determine scaling-in for a first DU. For example, the OAM modulemay determine scaling-in to remove the first DUfrom a DU pool that includes the first DU. In an embodiment of the present disclosure, the OAM modulemay identify that scaling-in is required based on information about the DU pool that includes the first DU. For example, the OAM modulemay determine scaling-in for the first DUbased on traffic of the DU pool to which the first DUbelongs, throughput (e.g., a maximum amount of available resources), currently available resource (e.g., an amount of remaining resources), etc.

8 FIG. 830 850 860 840 810 860 830 As shown in, a CUmay be connected to a plurality of DUs, i.e., the first DUand a second DUby a plurality of midhaul interfaces through the midhaul splitter module. In an embodiment of the present disclosure, the OAM modulemay configure a connection (or midhaul interface) between the second DUand the CUfor a target cell to be migrated.

810 850 820 810 820 850 860 810 820 The OAM modulemay transmit information about the determining of the scaling-in for the first DUto a scaling agent module. In an embodiment of the present disclosure, the OAM modulemay instruct the scaling agent moduleto perform a migration operation from the first DUto the second DUfor scaling-in. For example, the OAM modulemay provide information required for the scaling agent moduleto perform the migration operation.

820 850 850 860 820 850 860 870 820 850 860 870 820 852 854 856 850 862 864 866 860 The scaling agent modulemay identify the determining of scaling-in for the first DU, and perform a cell migration operation from the first DUto the second DUfor scaling-in. In an embodiment of the present disclosure, for the migration operation for scaling-in, the scaling agent modulemay control at least one of the first DU, the second DU, an RUor an inter-unit interface. For example, the scaling agent modulemay transmit an instruction to at least one of the first DU, the second DUor the RU. For example, the scaling agent modulemay control at least some of an RLC layer, an MAC layeror a PHY layerof the first DU, or an RLC layer, an MAC layeror a PHY layerof the second DU.

820 850 860 820 810 850 850 860 850 850 850 860 The scaling agent modulemay identify a target cell to be migrated from the first DUto the second DU. In an embodiment of the present disclosure, the target cell may be selected by the scaling agent moduleor the OAM modulefrom among one or more cells associated with the first DU, but is not limited thereto. For example, the target cell may be selected based on information (e.g., throughput, remaining resources, traffic, etc.) regarding the first DU, information regarding the second DU, information (e.g., traffic) regarding each cell associated with the first DU, etc. For example, the target cell may be randomly selected from among one or more cells associated with the first DU. In an embodiment of the present disclosure, in the case of scaling-in, all the cells associated with the first DUmay be migrated to the second DUas a target cell.

820 850 860 822 820 850 860 850 860 820 852 854 856 850 862 864 866 860 The scaling agent modulemay migrate, for scaling-in, a context associated with the target cell from the first DUto the second DUin. For example, the scaling agent modulemay control at least one of the first DUor the second DUto migrate the context associated with the target cell from the first DUto the second DU. The context associated with the target cell may include a cell context for the target cell itself, or a UE context for a UE associated with the target cell. In an embodiment of the present disclosure, the scaling agent modulemay migrate the context associated with the target cell included in at least one of the RLC layer, the MAC layeror the PHY layerof the first DUto at least one of the RLC layer, the MAC layeror the PHY layerof the second DU.

820 870 850 860 824 820 850 860 870 850 860 820 850 870 860 870 870 870 8 FIG. The scaling agent modulemay switch a fronthaul interface between the RUand the DU from the first DUto the second DUfor the target cell, in. For example, the scaling agent modulemay control at least one of the first DU, the second DUor the RUto switch the fronthaul interface from the first DUto the second DUfor the target cell. In an embodiment of the present disclosure, for the target cell, the scaling agent modulemay release the fronthaul interface between the first DUand the RU, and configure a fronthaul interface between the second DUand the RU. In other words, for the target cell, the RUmay be connected to one DU through the fronthaul interface. Hence, the RAN system ofmay not require the fronthaul splitter module for providing a plurality of fronthaul interfaces between the RUand the plurality of DUs for the target cell.

870 In the meantime, in an embodiment of the present disclosure, the RUmay be connected to a single DU for the target cell, but an RU associated with a plurality of cells may be connected to a first DU for a first cell and to a second DU for a second cell. In other words, the RU may be connected to a plurality of DUs through a plurality of fronthaul interfaces on a cell basis. Furthermore, in an embodiment of the present disclosure, a single DU may be connected to a plurality of RUs through a plurality of fronthaul interfaces.

850 850 830 850 860 850 In an embodiment of the present disclosure, as the migration of the target cell is completed, the first DUmay be removed from the DU pool. In an embodiment of the present disclosure, as the migration of the target cell is completed, the midhaul interface between the first DUand the CUmay be released. In an embodiment of the present disclosure, as all the cells included in the first DUare migrated to the second DU, the first DUmay be removed from the DU pool and the scaling-in operation may be completed.

820 822 824 850 860 5 7 FIGS.to Detailed operations of the scaling agent modulemigrating a context associated with the target cell inand switching fronthaul interfaces into migrate the target cell from the first DUto the second DUmay be performed according to the aforementioned one or more embodiments with reference to. For example, the one or more embodiments described for migration of a target cell for scaling-out will be equally applied to migration of a target cell for scaling-in. Similarly, the one or more embodiments described for migration of a target cell for scaling-in will be equally applied to migration of a target cell for scaling-out. Furthermore, in the present disclosure, the one or more embodiments described for migration of a target cell for scaling-in or scaling-out will be equally applied to migration of a target cell for occasions other than scaling-in or scaling-out.

820 810 820 810 820 810 8 FIG. The scaling agent moduleand the OAM moduleare separately shown in, but the disclosure is not limited thereto. For example, the scaling agent moduleand the OAM moduleare integrated in a single module, which may perform the functions and operations of the scaling agent moduleand the OAM module.

8 FIG. 850 860 850 860 The respective modules and entities ofmay be software modules, hardware modules and/or combinations thereof. For example, the first DUand the second DUare software modules, which may be included/stored in one hardware (e.g., a server device). For example, the first DUand the second DUmay be included/stored and executed in different hardware.

9 FIG. is a flowchart illustrating an example of a method of performing a cell migration operation for a DU, according to an embodiment of the present disclosure.

9 FIG. 9 FIG. 9 FIG. 900 910 940 910 940 910 940 900 Referring to, a methodby which an electronic device performs a cell migration operation for a DU may include operationsto. In an embodiment of the present disclosure, operationstomay be executed by at least one processor included in an electronic device. In an embodiment of the present disclosure, operationstomay be executed by an electronic device (e.g., at least one processor of the electronic device) that includes or performs the scaling agent module. The methodby which the electronic device performs the cell migration operation for a DU is not limited to what is shown in, and may further include an operation not shown inor omit some of the operations.

910 In operation, the electronic device may migrate a cell context for a target cell included in at least one of an RLC layer, an MAC layer or a PHY layer of a first DU to at least one of an RLC layer, an MAC layer or a PHY layer of a second DU.

920 In operation, the electronic device may configure a connection between the RLC layer of the first DU and the MAC layer of the second DU for the target cell, and identify that the target cell is in a state of being available for communication. In an embodiment of the present disclosure, the state of being available for communication may include a state of communication through the target cell satisfying a criterion. For example, the state of being available for communication may include a state that satisfies a criterion for communication delay, communication performance, processing capability, throughput, or the like.

930 In operation, the electronic device may migrate UE contexts for one or more target UEs among UE contexts for a plurality of UEs associated with the target cell, which are included in the RLC layer of the first DU, to the RLC layer of the second DU. In other words, the electronic device may migrate the UE contexts on a UE basis.

940 In operation, the electronic device may switch an F1-U interface for the one or more target UEs to the second DU from the first DU, and configure a connection (or a path or an interface) between the RLC layer and the MAC layer of the second DU for the one or more target UEs. For example, a connection is configured between RLC and MAC layers of the second DU for a migrated UE, and a connection is configured between the RLC layer of the first DU and the MAC layer of the second DU for a non-migrated UE. As there are as many F1-U interfaces as the number of radio bearers of UEs, it may be difficult for migration from the first DU to the second DU for all the UEs at once. Hence, the electronic device may migrate the UE context of the RLC layer and the F1-U interface on a UE basis rather than in a whole cell unit.

10 FIG. is a flowchart illustrating an example of a method of performing a cell migration operation for a DU, according to an embodiment of the present disclosure.

10 FIG. 10 FIG. 10 FIG. 1000 1010 1032 1010 1032 1010 1032 1000 Referring to, a methodby which an electronic device performs a cell migration operation for a DU may include operationsto. In an embodiment of the present disclosure, operationstomay be executed by at least one processor included in the electronic device. In an embodiment of the present disclosure, operationstomay be executed by an electronic device (e.g., at least one processor of the electronic device) that includes or performs the scaling agent module. The methodby which the electronic device performs the cell migration operation for a DU is not limited to what is shown in, and may further include an operation not shown inor omit some of the operations.

1010 In operation, the electronic device may migrate cell contexts for the target cell in the RLC layer, the MAC layer and the PHY layer in the first DU to the RLC layer, the MAC layer and the PHY layer in the second DU.

1012 In operation, the electronic device may switch the fronthaul interface for the target cell from the first DU to the second DU based on the migrating of the cell context for the target cell. For example, the electronic device may switch the fronthaul interface for the target cell from the first DU to the second DU after the migration of the cell context for the target cell.

1014 In operation, the electronic device may migrate UE contexts for a plurality of UEs (e.g., all UEs) in the target cell of the MAC and PHY layers of the first DU to the MAC and PHY layers of the second DU, based on the migrating of the cell context for the target cell. For example, the electronic device may migrate UE contexts for all UEs in the target cell of the MAC and PHY layers of the first DU to the MAC and PHY layers of the second DU, after the migration of the cell context for the target cell.

1016 In operation, the electronic device may configure a connection between the RLC layer of the first DU and the MAC layer of the second DU based on the migrating of the UE context to the MAC and PHY layers of the second DU. For example, the electronic device may configure a connection between the RLC layer of the first DU and the MAC layer of the second DU after the migration of the UE context to the MAC and PHY layers of the second DU.

1014 1016 1012 1014 1016 1012 In an embodiment of the present disclosure, the electronic device may perform operationsandin parallel with operation. For example, the electronic device may perform operationsandat the same time as the operation.

1018 In operation, the electronic device may identify whether a communication service of the target cell is provided successfully. In an embodiment of the present disclosure, the electronic device may identify whether the UE associated with the target cell is successfully accessible to a communication network through the target cell. In an embodiment of the present disclosure, the electronic device may identify whether the target cell is in a state of being available for communication. In an embodiment of the present disclosure, whether a communication service of the target cell is provided successfully may be determined. In an embodiment of the present disclosure, information about whether a communication service of the target cell is provided successfully may be received.

1010 1016 Based on identifying that the communication service of the target cell is not successfully provided, the electronic device may re-perform at least one of operationsto.

1020 In operation, based on identifying that the communication service of the target cell is successfully provided, the electronic device may remove the migrated UE contexts and cell contexts for the target cell from the MAC and PHY layers of the first DU. For example, after identifying that the communication service of the target cell is successfully provided (or in response to the identifying), the electronic device may remove the migrated UE contexts and cell contexts for the target cell from the MAC and PHY layers of the first DU.

1022 In operation, the electronic device may select one or more target UEs to be migrated to the second DU from among one or more UEs in the target cell existing (or included) in the RLC layer of the first DU. In an embodiment of the present disclosure, the electronic device may select one or more target UEs to be migrated to the RLC layer of the second DU from among one or more UEs that have not been migrated to the RLC layer of the second DU.

1024 In operation, the electronic device may migrate UE contexts for the selected one or more target UEs to the RLC layer of the second DU.

1026 In operation, the electronic device may change (or switch) the F1-U path (i.e., F1-U interface) of the one or more target UEs migrated to the RLC layer of the second DU from the first DU to the second DU.

1028 In operation, the electronic device may change (or switch) the RLC layer-to-MAC layer path of the one or more target UEs migrated to the RLC layer of the second DU from the first DU-to-second DU path (i.e., a path from the RLC layer of the first DU to the MAC layer of the second DU) to the second DU-to-second DU path (i.e., a path from the RLC layer of the second DU to the MAC layer of the second DU). For example, the electronic device may configure a connection between the RLC and MAC layers of the second DU for the migrated one or more target UEs.

1030 In operation, the electronic device may identify whether there is a UE to be migrated in the RLC layer of the first DU, i.e., a UE that has not been migrated among one or more UEs in the target cell. In an embodiment of the present disclosure, the electronic device may identify whether there is a UE to be migrated left in the RLC layer of the first DU.

1022 1028 Based on identifying that there is a UE to be migrated, the electronic device may re-perform at least one of operationsto.

1032 In operation, based on identifying that there is no UE to be migrated, i.e., that UE contexts for all UEs in the target cell have been migrated to the RLC layer of the second DU, the electronic device may delete (or remove) information relating to the migrated target cell in the RLC layer of the first DU. For example, the electronic device may delete UE contexts and cell contexts for the target cell included in the RLC layer of the first DU.

In an embodiment of the present disclosure, based on completion of the cell migration, the electronic device may transmit information indicating that the cell migration has been completed to a network element management system (EMS) (or a configuration module managed by a mobile carrier's operator).

10 FIG. 1024 1028 1024 1028 Although the electronic device is shown inas performing operationstoin sequence, it is not limited thereto. For example, the electronic device may perform at least some of operationsandat the same time.

10 FIG. 1024 1026 1028 The electronic device is shown inas deleting the UE contexts included in the RLC layer of the first DU after migrating all the UEs from the first DU to the second DU, but it is not limited thereto. For example, the electronic device may delete (or remove) the UE contexts migrated to the RLC layer of the second DU after at least one of operations,or. In other words, whenever a UE is migrated to the second DU, the electronic device may delete the UE context for the migrated UE. For example, the electronic device may delete UE contexts for migrated UEs periodically or aperiodically.

10 FIG. 1000 1010 1020 1022 1032 As shown in, the methodby which the electronic device performs a cell migration operation for a DU may include operationstoof migration of MAC and PHY layers and the fronthaul interface, and operationstoof migration of the midhaul interface and RLC layer. In an embodiment of the present disclosure, as for vDU scaling, the migration method for MAC and PHY layers and fronthaul interfaces and the migration method for the midhaul interfaces and RLC layer may be different. For example, to reduce complexity that may occur from operation of two fronthaul interfaces and an MAC scheduler, the electronic device may migrate information at once on a cell basis in each stage of migrating MAC and PHY layers and fronthaul interfaces while performing migration on a UE basis for stable migration operation in each stage of migrating midhaul interfaces and RLC layer.

11 FIG. is a diagram illustrating an example of an electronic device for performing a cell migration operation for a DU, according to an embodiment of the present disclosure.

1100 1100 11 FIG. An electronic deviceshown inis one for performing a cell migration operation for a DU, which may be a server device. For example, the electronic deviceis a communication device that constitutes a RAN, which may be a server device that exists to constitute the RAN, such as a server device that performs an RU function, a server device that performs a DU function, a server device that performs a CU function, or a server device that performs an OAM function, etc., or an extra server device that controls cell migration (e.g., a scaling agent device).

1100 1110 1120 In an embodiment of the present disclosure, the electronic devicemay include at least one processorand a memory, but is not limited thereto.

1110 1100 1100 1110 1110 1100 The processormay be electrically connected to components included in the electronic deviceto perform computation or data processing for controlling and/or communicating of the components included in the electronic device. In an embodiment of the present disclosure, the processormay load the request, command or data received from at least one of the other components onto the memory, process it, and store a resultant data in the memory. The processormay be configured with one or more processors to control a series of processes for operating the electronic deviceaccording to the aforementioned embodiments.

1110 1110 1110 One or more processors included in the processormay be such circuitries as system on chips (SoCs), integrated circuits (ICs), etc. One or more processors included in the processormay be a universal processor such as a central processing unit (CPU), a microprocessor unit (MPU), an application processor (AP), a digital signal processor (DSP), etc., a dedicated graphic processor such as a graphic processing unit (GPU), a vision processing unit (VPU), etc., a dedicated AI processor such as a neural processing unit (NPU) or a dedicated communication processor such as a communication processor (CP). When the one or more processors included in the processorare the dedicated AI processors, the dedicated AI processors may be designed in a hardware structure that is specific to dealing with a particular AI model.

1110 The processormay include various processing circuits and/or a plurality of processors. For example, the term ‘processor’ used in the present disclosure including claims may include various processing circuits including at least one processor. One or more of the at least one processor may be individually and/or collectively, in a distributed method, configured to perform one or more functions of the present disclosure. In the present disclosure, when the processor, the at least one processor, or the one or more processors are described as being configured to perform multiple functions, it may include a situation in which one processor performs some of the functions while the other processor(s) performs some other functions, and a situation in which a single processor performs all the functions. Furthermore, the at least one processor may include a combination of processors that perform various functions in a distributed manner. The at least one processor may execute program instructions to fulfill or perform various functions.

1110 1120 1120 1120 1110 1120 1110 1120 1110 1120 The processormay record data in the memoryor read out data stored in the memory, and especially, execute the program or the at least one instruction stored in the memoryto process data according to a predefined operation rule or AI model. The processormay control processing of input data according to a predefined operation rule, an algorithm, a method or a model stored in the memory. The processormay control processing of input data based on data stored in the memory. By using the input data, the processormay perform operations of the predefined operation rule, algorithm, method or model stored in the memory.

1120 1110 1100 1120 1110 The memorymay be electrically connected to the processor, and may store one or more modules, algorithms, operation rules, models, programs, instructions or data related to operations of the components included in the electronic device. For example, the memorymay store one or more modules, algorithms, operation rules, models, programs, instructions or data for processing and control of the processor.

1120 1120 1110 1120 1120 1120 1110 1110 The memorymay be configured with storage media or a combination of the storage media such as a flash memory, a hard disk, a multimedia card micro type memory, a card type memory (e.g., secure digital (SD) or extreme digital (XD) memory), a random access memory (RAM), a static RAM (SRAM), a read only memory (ROM), an electrically erasable programmable ROM (EEPROM), a programmable ROM (PROM), a magnetic memory, a magnetic disk, and an optical disk. The memorymay not be separately present but integrated into the processor. The memorymay include a volatile memory, a non-volatile memory, or a combination of the volatile memory and the non-volatile memory. The memorymay store a program or at least one instruction for performing operations according to the aforementioned embodiments. The memorymay also provide the stored data to the processorat the request of the processor.

1120 1100 1120 1100 In an embodiment of the present disclosure, the memorymay store data or information identified, obtained, generated or determined by the electronic device. The memorymay store the data or information identified, obtained, generated or determined by the electronic devicein a compressed format.

1100 1120 1100 1120 1110 1120 1110 1100 Some modules for performing at least one operation of the electronic devicemay be implemented as hardware modules, software modules and/or a combination thereof. The memorymay include software modules for performing at least some of the aforementioned operations of the electronic device. In an embodiment of the present disclosure, the modules included in the memorymay be executed by the processorto perform operations. For example, the modules (i.e., the software modules) included in the memorymay be executed under the control or instruction of the processor, and may include programs, models or algorithms configured to perform operations to derive output data for input data. Some modules for performing at least one operation of the electronic devicemay be configured with a plurality of submodules or a single module.

1100 1100 1100 11 FIG. The electronic devicemay include more components than those as shown in. In an embodiment of the present disclosure, the electronic devicemay further include a communication interface (or communication module) to communicate with an external device. In an embodiment of the present disclosure, the electronic devicemay further include an input/output device and/or an input/output interface.

1 11 FIGS.to 1 11 FIGS.to In the present disclosure, overlapping descriptions in connection withmay not be repeated, and the aforementioned one or more embodiments ofmay be applied/practiced in combination. In the present disclosure, an operation described as being performed by a module may be executed/performed by an electronic device that includes or stores the module, or executed/performed under the control of at least one processor of the electronic device that includes the module. An operation described as being performed by an electronic device may be executed/performed by a module included or stored in the electronic device, or performed under the control of at least one processor of the electronic device by using the module included or stored in the electronic device.

In an embodiment of the present disclosure, a method performed by an electronic device may include migrating a cell context for a target cell included in at least one of a radio link control (RLC) layer, a medium access control (MAC) layer or a physical (PHY) layer in a first distributed unit (DU) to at least one of an RLC layer, an MAC layer or a PHY layer in a second DU. In an embodiment of the present disclosure, the method may include configuring a connection between the RLC layer of the first DU and the MAC layer of the second DU for the target cell, and identifying that the target cell is in a state of being available for communication. In an embodiment of the present disclosure, the method may include migrating user equipment (UE) contexts for one or more target UEs among UE contexts for a plurality of UEs associated with the target cell, which are included in the RLC layer of the first DU, to the RLC layer of the second DU. In an embodiment of the present disclosure, the method may include switching an F1-U interface for the one or more target UEs to the second DU from the first DU, and configuring a connection between the RLC layer and the MAC layer in the second DU for the one or more target UEs.

According to an embodiment of the present disclosure, as communication is continued for the target cell in the first DU, there may be no time limit to migrating the cell context for the target cell, and thus, the target cell may be configured in the second DU without interrupting the communication service. According to an embodiment of the present disclosure, by migrating the UE context in the RLC layer and the F1-U path on a UE basis, operation stability may be secured, and system reliability may be improved.

In an embodiment of the present disclosure, the method may include switching the fronthaul interface for the target cell from the first DU to the second DU based on the migrating of the cell context for the target cell. According to an embodiment of the present disclosure, as two MAC schedulers use air resources (or radio resources) for one RU (or cell) without dividing the air resources and only one MAC is valid at one time, the complexity of MAC scheduling operations may be reduced. According to an embodiment of the present disclosure, the fronthaul interface may be prevented from communicating with two H-PHY layers. In other words, the fronthaul interface does not operate by being switched between two H-PHY layers, but may handle communication only for the second DU after being switched from the first DU to the second DU for a particular time. It may avoid a situation in which the fronthaul interface is connected to two H-PHY layers at the same time, and prevent the use of additional resources for packet distribution.

In an embodiment of the present disclosure, the method may include migrating the UE contexts for the plurality of UEs included in at least one of the MAC layer or PHY layer of the first DU to at least one of the MAC layer or PHY layer of the second DU based on the migrating of the cell context for the target cell.

In an embodiment of the present disclosure, the method may include removing the cell context for the target cell and the UE contexts for the plurality of UEs from at least one of the MAC layer or the PHY layer of the first DU based on identifying that the target cell is in a state of being available for communication.

In an embodiment of the present disclosure, the method may further include selecting one or more target UEs from among the plurality of UEs.

In an embodiment of the present disclosure, the method may further include removing UE contexts for the one or more target UEs from the RLC of the first DU based on migration of the UE contexts for the one or more target UEs.

In an embodiment of the present disclosure, the method may further include removing the cell context for the target cell from the RLC of the first DU based on completion of the migrating of the UE contexts for the plurality of UEs to the RLC of the second DU.

In an embodiment of the present disclosure, the method may further include identifying determination of scaling-out for the first DU.

In an embodiment of the present disclosure, based on the determining of the scaling-out for the first DU, the second DU may be generated and a midhaul interface may be configured between a centralized unit (CU) for the first DU and the second DU.

In an embodiment of the present disclosure, the method may further include identifying determination of scaling-in for the first DU.

In an embodiment of the present disclosure, a program for causing a computer to perform the method may be recorded on a computer-readable recording medium.

In an embodiment of the present disclosure, an electronic device may include a memory storing one or more instructions and at least one processor configured to execute the one or more instructions stored in the memory. In an embodiment of the present disclosure, the at least one processor may execute the one or more instructions to migrate a cell context for a target cell included in at least one of a radio link control (RLC) layer, a medium access control (MAC) layer or a physical (PHY) layer in a first distributed unit (DU) to at least one of an RLC layer, an MAC layer or a PHY layer in a second DU. In an embodiment of the present disclosure, the at least one processor may execute the one or more instructions to configure a connection between the RLC layer of the first DU and the MAC layer of the second DU for the target cell, and identify that the target cell is in a state of being available for communication. In an embodiment of the present disclosure, the at least one processor may execute the one or more instructions to migrate user equipment (UE) contexts for one or more target UEs among UE contexts for a plurality of UEs associated with the target cell, which are included in the RLC layer of the first DU, to the RLC layer of the second DU. In an embodiment of the present disclosure, the at least one processor may execute the one or more instructions to switch an F1-U interface for the one or more target UEs to the second DU from the first DU, and configure a connection between the RLC layer and the MAC layer in the second DU for the one or more target UEs.

In an embodiment of the present disclosure, the at least one processor may execute the one or more instructions to switch the fronthaul interface for the target cell from the first DU to the second DU based on the migrating of the cell context for the target cell.

In an embodiment of the present disclosure, the at least one processor may execute the one or more instructions to migrate the UE contexts for the plurality of UEs included in at least one of the MAC layer or PHY layer of the first DU to at least one of the MAC layer or PHY layer of the second DU based on the migrating of the cell context for the target cell.

In an embodiment of the present disclosure, the at least one processor may execute the one or more instructions to remove the cell context for the target cell and the UE contexts for the plurality of UEs from at least one of the MAC layer or the PHY layer of the first DU based on identifying that the target cell is in a state of being available for communication.

In an embodiment of the present disclosure, the at least one processor may execute the one or more instructions to select one or more target UEs from among the plurality of UEs.

In an embodiment of the present disclosure, the at least one processor may execute the one or more instructions to remove UE contexts for the one or more target UEs from the RLC of the first DU based on migration of the UE contexts for the one or more target UEs.

In an embodiment of the present disclosure, the at least one processor may execute the one or more instructions to remove the cell context for the target cell from the RLC of the first DU based on completion of the migrating of the UE contexts for the plurality of UEs to the RLC of the second DU.

In an embodiment of the present disclosure, the at least one processor may execute the one or more instructions to identify a determination of scaling-out for the first DU. In an embodiment of the present disclosure, based on the determining of the scaling-out for the first DU, the second DU may be generated and a midhaul interface may be configured between a centralized unit (CU) for the first DU and the second DU.

In an embodiment of the present disclosure, determination of scaling-in for the first DU may be identified.

The machine-readable storage medium may be provided in the form of a non-transitory storage medium. The term ‘non-transitory storage medium’ may mean a tangible device without including a signal, e.g., electromagnetic waves, and may not distinguish between storing data in the storage medium semi-permanently and temporarily. For example, the non-transitory storage medium may include a buffer that temporarily stores data.

In an embodiment, the aforementioned method according to the various embodiments of the disclosure may be provided in a computer program product. The computer program product may be a commercial product that may be traded between a seller and a buyer. The computer program product may be distributed in the form of a machine-readable storage medium (e.g., a CD-ROM) or distributed directly between two user devices (e.g., smart phones) or online (e.g., downloaded or uploaded). In the case of the online distribution, at least part of the computer program product (e.g., a downloadable app) may be at least temporarily stored or arbitrarily created in a storage medium that may be readable to a device such as a server of the manufacturer, a server of the application store, or a relay server.